Electrical switch



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ELECTRICAL SWITCH Original Filed Dec. 5, 1962 '7 Sheets-Sheet 5 I INVEILTORS Z ax'flarilij 4 75241261402 'T. J. RYS ETAL ELECTRICAL swn'ca Oct. 10, 1967 7 Sheets-Sheet 6 Original Filed Dec. 5. 1962 Oct. 10, 1967 T. J. R-Ys ETAL 3,346,711

ELECTRICAL SWITCH Original Filed Dec. 5, 1962 7 Sheets-Sheet 7 J24 Jz United States Patent 3,346,711 ELECTRICAL SWITCH Tadeusz .I. Rys and Harris I. Stanback, Lexington, Ky., assignors to Square B Company, Fark Ridge, Ill, a corporation of Michigan Original application Dec. 5, 1962, Ser. No. 242,423, now Patent No. 3,240,888, dated Mar. 15, 1966. Divided and this application Sept. 20, 1965, Ser. No. 488,531

15 Claims. (Cl. 200- -114) ABSTRACT OF THE DISCLOS A multipole fusible safety switch having a plurality of generally flat, edgewise-pivotable switch blades pivotally mounted respectively on rigid leg portions of a plurality of fuse clips and extending through a pivotally mounted blade actuator carrying a plurality of springs respectively engaged with the switch blades. The springs establish contact pressure when the switch blades are engaged respectively with a plurality of stationary contacts, aid in maintaining the switch blades respectively in their pivotal mounting, and also aid in maintaining the blade actuator in its pivotal mountin' This is a division of copending application, Ser. No. 242,423, filed Dec. 5, 1962, and now issued as Patent No. 3,240,888, dated Mar. 15, 1966.

This invention relates generally to electrical switches, and more particularly to enclosed or safety switches.

An object of the invention is to provide an improved safety switch.

Another object is to provide an improved safety switch of the single throw, single make and break type.

A further object is to provide an improved inultipole safety switch.

Yet another object is to provide an improved multipole safety switch in which a pivotally mounted blade carrier carries a plurality of pivotally mounted blades respectively adapted to engage a plurality of stationary contacts and also carries a corresponding plurality of biasing springs, each biasing spring being operatively associated with one of the blades intermediately of the ends of the blade to retain one end portion of the blade in its pivotal mounting and to establish pressure between the other end portion of the blade and its respective stationary contact when the blade and contact are engaged, and the biasing springs also being operatively associated with the blade carried to aid in retaining the blade carrier in its pivotal mounting.

Still another object is to provide an improved multipole safety switch of the fusible type.

A still further object is to provide an improved multipole fusible safety switch including a base, a plurality of pairs of axially aligned fuse holders mounted on the base, a plurality of stationary contact members mounted on the base and respectively spaced generally axially from the pairs of fuse holders, a blade carrier pivotally mounted on the base, a plurality of switch blades carried by the blade carrier and having first end portions respectively engagable with the stationary contact members and second end portions respectively pivotally mounted on the fuse holders of each pair closer to the stationary contact members, and a plurality of biasing springs carried by the blade carrier and respectively operatively associated with the switch blades between the end portions thereof to establish pressure between the first end portions thereof and the stationary contact members when the first end portions of the switch blades are in engagement with the stationary contact members and to retain the second end 3,345,711 Patented Oct. 10, 1967 portions of the switch blades in pivotal engagement with the fuse holders of each pair closer to the stationary contact members, the biasing springs also being operatively associated with the blade carrier to aid in retaining the blade carrier in pivotal engagement with the base.

Another object is to provide an improved multipole fusible safety switch in which a minimum number of electrical joints is provided between the fuse holder of each fusible pole and the corresponding electrical connector for a power supply line.

Other objects and advantages will appear when the following specification is considered along with the accompanying drawings in which:

FIG. 1 is a front elevational view of a fusible safety switch constructed in accordance with the invention;

FIG. 2 is a side elevational view of the switch of FIG. 1;

FIG. 3 is a top view of the switch of FIG. 1;

FIG. 4 is a fragmentary perspective view of the switch of FIG. 1 showing particularly the latch for the front cover;

FIG. 5 is a front elevational view of the switch of FIG. 1 with the cover and certain other portions removed, and certain other parts broken away or in section, the switch blades being shown in on position;

FIG. 6 is a view taken substantially along section line 66 of FIG. 5;

FIG. 7 is a view taken substantially along section line 7 7 of FIG. 5;

FIG. 7a is a fragmentary sectional view showing a modified form of the fuse clips of FIG. 7;

FIG. 8 is a view taken substantially along section line 8-8 of FIG. 5;

FIG. 9 is a view taken substantially along section line 9? of FIG. 5 but showing the switch blades in off position;

FIG. 10 is a perspective view of the blade carrier of the switch of FIG. 1;

FIG. 11 is a sectional view taken substantially along the line 11-11 of FIG. 10;

FIG. 12 is a sectional view of the 10 taken substantially as FIG. 11;

FIG. 13 is a sectional view of the blade carrier of FIG. 10 taken substantially as indicated by line 1313 of FIG. 11;

FIG. 14 is a perspective view of one of the arc shields of the switch of FIG. 1;

FIG. 15 is a fragmentary view similar to FIG. 2 but with portions of the box and cover broken away, the operating mechanism of the switch being shown in on position;

FIG. 16 is a fragmentary front elevational view of the operating mechanism of the switch, portions of the cover and the latch therefor being broken away;

FIG. 17 is a view of portions of the operating mechanism shown in FIG. 15, but illustrating a different position thereof for defeating the switch and cover interlock means;

FIG. 18 is a view taken substantially along section line 18'18 of FIG. 16, but showing the operating mechanism of the switch in off position;

FIG. 19 is a view taken substantially along section line 19-19 of FIG. 18;

FIG. 20 is a perspective view of the operating cam of the switch operating mechanism; and

FIG. 21 is a fragmentary perspective view of a portion of the handle of the switch operating mechanism.

With reference to the drawings, and particularly to blade carrier of FIG. indicated by line 1212 of cordance with the invention includes an open-front metal box 32 closable by a cover 34 hinged to the left-hand side thereof as viewed in FIG. 1. An operating handle 36 for the switch is mounted for pivotal movement between on and off positions on a pin 38 which has a slotted head, and, as hereinafter described, forms part of a defeata-ble interlock means for the switch operating handle 36 and the cover 34. For compactness and to permit mounting of a plurality of switches 30 in closely spaced side-by-side relationship, the operating handle 36 is formed and arranged to be generally within the broad outline of the box 32 and cover 34. The cover 34 is provided with flange portions which overlap the front edges of the box 32, but is cut away adjacent the handle 36 and is provided with an aperture 40 for the reception of an ear 42, to be hereinafter more fully described, having a hole 43 therein for the reception of a padlock hasp to lock the cover 34 closed. A latch member 44, also to be more fully described hereinafter, is provided for latching cover 34 closed when a padlock is not used in the ear 42. The latch member 44 has a tongue 45 engageable with the outside of the cover 34 to retain it in closed position. The tongue 45 nonmally prevents opening and closing of the cover 34 when the handle 36 is in on position; but when the handle 36 is in off position, and also when the defeatable interlock means is operated by the turning of the pin 38 with a screwdriver when the handle 36 is in on position, the outer end of the latch member 44 may be resiliently deformed as more fully described hereinafter to release the cover 34 from the tongue 45.

A hole 46 is provided in the handle 36 and a hole 48 is provided in the latch member 44, a padlock hasp inserted in either of the holes 46 and 48 serving to prevent operation of the handle 36 from one extreme position to the other and thus effectively locking the switch blades, to be later described, in open or closed position.

In FIGS. 9, a molded insulating "base 50 is shown secured to the back of the box 32 in any suitable manner. The fastening means shown includes a pair of screws 51 (FIGS. 5 and 9) threaded into the back of the box and a hook 52 formed on the back of the box and adapted to be received in a recess 53 to retain the base. The base 50 serves as a mounting for a four-pole solid-neutral switch including three fusible poles having cooperable contacts and one solid-neutral pole. The solid-neutral pole includes a solid-neutral strap 55, an electrical connector 56 for the neutral wire of a four-wire, three-phase source of electrical power, an electrical connector 57 for the neutral wire of a four-wire three-phase load, and an electrical connector 58 for the connection to ground. A single screw 60 secures the strap 55 and the connector 58 to the base, and the connectors 56' and 57 are held in suitable recesses in the base by opposite ends of the strap 55. For threewire ungrounded systems, the solid-neutral strap 55 and its associated connectors may be eliminated.

Each of the three fusible poles includes an upper and a lower composite fuse holder, the upper one having a switch bla'de pivotally mounted thereon and the lower one having a load terminal associated therewith. Further, each composite fuse holder includes a relatively rigid conductive portion and a resilient clamping portion. Thus, as shown best in FIG. 7, upper fuse holders including relatively rigid conductive portions 62a, 62b, and 620 and resilient clamping portions 63a, 63b, and 630 are secured to the base 50 by means of screws 64a, 64b, and 640 which are threaded into the relatively rigid portions 62a, 62b, and 62c, respectively. The resilient clamping portions and the relatively rigid portions are substantially L-shaped, but the relatively rigid portions are curved to form pockets for ferrules of cartridge fuses and are additionally provided with holes forming pivotal bearing surfaces for switch blades 66a, 66b, and 660, respectively, which have protuberances 65a, 65b, and 65c projecting into the bearing holes.

In FIG. 7a, a modified form of the resilient clamping portion of a composite fuse holder is shown. Thus, if desired, the L-shaped resilient clamping portions 63a, 63b, and 63c may be replaced by resilient clamping portions such as a generally U-shaped clamping portion 63g, which is similar to the L-shaped clamping portions 63a, 63b, and 630, but has an additional leg extending over a switch blade 66g to aid in retaining a protuberance 65g thereof in a bearing hole in a relatively rigid conductive portion 62 g of a composite fuse holder.

As shown in FIGS. 5, 8, and 9, the lower fuse holders including resilient clamping portions 63d, 63c, and 63 and relatively rigid conductive portions 63a, 68b, and 68c are scoured to the base 50 by means of screws 6411, 64c, and 64 which are threaded into the relatively rigid portions 68a, 68b, and 68c, respectively. The relative rigid portions 68a, 68b, and 680 of the lower fuse holders differ from the relatively rigid portions 62a, 62b, and 62c of the upper fuse holders in that they do not have switch blades associated therewith, and they are provided with extensions parallel to the base 50 for securing electrical connectors 57a, 57b, and 570 respectively thereto, as best shown in FIG. 8. The electrical connectors 57a, 57b, and 570 respectively form the load terminals of the three fusible poles.

Electrical connectors 56a, 56b, and 560 forming the line terminals of the three fusible poles are secured to the base 50 by extensions of generally L-shaped stationary contact members 70a, 70b, and 70c, respectively, which in turn are secured to the base 50 by means of screws 64g, 64h, and 64i. The line terminals or electrical connectors 56, 56a, 56b, and 56c and the load terminals or connectors 57, 57a, 57b, and 57c are preferably of the type shown and described in a copending application, now Patent No. 3,133,781, issued May 19, 1964. The contact areas of the upstanding leg portions of the generally L-shaped stationary contact members 70a, 70b, and 700 engageable by the switch blades 66a, 66b, and 660 are shielded from the line terminals 56a, 56b, and 560 by insulating members 72a, 72b, and 720 respectively, which are identical to insulating member 72 shown in FIG. 14, a small apertured portion 73 of each insulating member being secured between the base 50 and a leg portion of a stationary contact member 70 extending parallel to the base 50.

The switch blades 66a, 66b, and 660, while being pivotally mounted on the relatively rigid portions 62a, 62b, and 620, respectively, of the upper fuse holders, are also mounted in a molded insulating blade actuator or carrier 76 forming an important part of this invention. The blade carrier 76 is formed with appropriate slots for respectively receiving the switch blades, as can best be seen in FIGS. 11-13, and also with appropriate pockets for respectively receiving compression springs 78a, 78b, and 78c, the spring pockets intercepting the blade slots so that one end of each spring is seated on a blade. The blade carrier 76 is pivotally mounted on the base 50, and more specifically on a pair of upstanding post portions 80 and 81 having recesses or slots 82 and 83 in respective corre sponding sides thereof. The carrier is provided with recesses 86 and 87 for laterally receiving post portions 80 and 81, respectively, and with cylindrical projections 88 and 89 which are adapted to be laterally received in the recesses or slots 82 and 83, respectively. The arrangement may be Visualized best from FIG. 10 in which the post portions 80 and 81 are shown in phantom. In assembling, the carrier without switch blades is placed on the post portions but offset from its final assembled position thereon so that the projections 83 and 89 will clear the post portions. Thereafter, the carrier is shifted laterally of the post portions to place the projections 88 and 89, respectively, in the slots 82 and 83, and engagement of the projections with the closed ends of the slots then prevents removal of the carrier directly axially of the post portions. The switch blades 66a, 66b, and 660 are then inserted in the blade carrier and projecting portions 65a, 65b, and 65c inserted in the bearing holes of the rigid portions 62a, 62b, and 620 of the upper fuse clips, the switch blades and associated springs 78a, 78b, and 78c then preventing shifting of the carrier back laterally of the post portions and thus maintaining the projections 88 and 89 in the slots 82 and 83.

The base 50 is provided with a slot 92 (FIG. 9) through which a projection 93 on the blade carrier 76 extends to limit pivotal movement of the carrier in a switch opening direction by engagement with the base 50 at the end of the slot, as shown in FIG. 9.

A lug 95 is provided on one end of the blade carrier 76 for cooperation with an operating cam 96 shown in FIGS. 15-20, the cam being best shown in FIG. 20 and the cooperative relationship between the lug 95 and the cam being illustrated in FIGS. 15, 16, and 18. The cam 96 is provided with a hole 97 (FIG. 20) for receiving the inner end of the pin 38 on which it is fixedly mounted for rotation therewith as a unit. The pin 38 is supported by bearing holes formed in an outwardly offset portion 99 of the right-hand side of the box 32 and in a formed plate 101) which overlaps the offset portion 99 and is riveted to the inside of the right-hand side of the box by a pair of rivets 101a and 1111b. The car 42 previously described is an integral part of the plate 100.

The handle 36 is pivotally mounted on the pin 38 between offset portion 99 of the box and plate th, a hole 103 (FIG. 21) being provided for this purpose, and an inwardly projecting lug 104 is provided radially of the hole 103 on the fiat inner end of the handle, the plate 100 having an arcuate slot 106 through which the lug 104 projects into a slot 108 in the cam 96.

A quick-make and quick-break action between the switch blades 66a, 66b, and 660 and the stationary contact members 70a, 70b, and 700, respectively, is provided by an over-center compression spring 110 operatively connected to the cam 96. The spring 110 is retained on an actuator 112 which extends therethrough and is reciprocally mounted in a bracket 113 formed integrally with the plate 100, the spring being compressed between the bracket 113 and a shouldered portion 114 on the actuator. The actuator 112 includes a pin 116 having an enlarged head portion, the pin 116 being received in a generally T-shaped slot 117 formed in the cam 96.

The cam 96 is provided with a pair of inwardly offset blade carrier actuating portions 120 and 121 having respective cam surfaces 122 and 123 alternatively engageable with the lug 95 on opposite sides thereof. The pivotal movement of the cam 96 in opposite directions is limited by a stop engaging projection 124 thereon having a surface 125 engageable with a flange 128 on the formed plate 100 and a surface 126 engageable with a stop 129 formed on the plate 106. A locking tongue 130 on the cam 96 is cooperable with a tongue 132 formed on the latch member 44, as best shown in FIG. 15. The latch member 44 is pivotally mounted on the pin .38 but is prevented from rotating by engagement of the tongue 132 in a notch 133 (FIG. 18) provided in the plate 100.

When the switch is in on position, the locking tongue 130 is normally aligned with the tongue 132 and substantially prevents bending of the outer end of the latch member 44, and the tongue 45 on the latch member interferes with opening and closing of the cover 34. Further, this interlock may not be defeated by merely moving the handle 36 part way toward off position of the switch without disengaging the blades 66a, 66b, and 660 from the stationary cont-act members 70a, 7111), and 70c, for when the handle 36 is moved far enough for the lug 194 thereon to rotate the locking tongue 130 out of alignment with the tongue 132, the handle 36 itself then prevents bending of the outer end of the latch member 44 and maintains the tongue 45 in interfering relationship with the cover 34. However, the interlock can be defeated by turning the pin 38 sufliciently to rotate the locking tongue 130 out of alignment with the tongue 132, as shown in FIG. 17, thus allowing the outer end portion of the latch member 44 to be bent sufficiently to move the tongue 45 out of interfering relationship with the cover 34 so that the cover can be opened by authorized persons while the switch is in on position. It is unlikely that unauthorized persons will known that the pin 38 may be turned to defeat the interlock.

A torsion spring 134 is provided to bias the handle 36 toward its extreme positions. One end of the spring 134 is anchored in a bracket portion 135 of the formed plate 101 and the other end is connected to the handle 36. The spring is pre-stressed so that it tends to unwind. Thus, in FIG. 15, the spring tends to rotate the handle 36 clockwise toward off position, and in FIG. 18, where it is viewed from the opposite side, the spring tends to rotate the handle 36 clockwise toward on position.

The slot 198 in the cam 96 has a longer arcuate length than the lug 104 on the handle 36 to provide a lost-motion connection enabling the over-center spring 110 to operate the cam 96 with a snap action without any restraint by the handle once the line of action of the spring has shifted across the pivotal axis of the cam. The snap movement of the cam is enhanced by the lost-motion connection between the pin 116 and the generally T-shaped slot 117, a shifting of the pin across the head of the T having an impact effect on the cam as the line of action of the spring 110 is shifted across the pivotal axis of the cam. Further, the cam surfaces 122 and 123 are spaced farther apart than the width of the lug on the blade carrier 76 to provide a lost-motion connection enabling the cam to enter its snap movement before sufiicient opening movement of the blade carrier 76 occurs to cause disengagement of the switch blades 66a, 66b, and 660 from the stationary contact members 70a, 70b, and 700.

The lost-motion connections between the handle 36 and cam 96 and between the cam 96 and blade carrier 76 also enable the cam 96 to be turned by the screw 38 to defeat the interlock between the cover 34 and handle 36.

Various modifications may be made in the structure disclosed without departing from the spirit and scope of the invention.

We claim: I

1. A fusible electrical switch comprising a pair of aligned fuse holders adapted to hold opposite end portions of a fuse, a stationary contact member mounted generally in alignment with said pair of fuse holders, a pivotally mounted blade actuator adjacent one of said fuse holders closer to said stationary contact member, and a switch blade pivotally mounted on a portion of said one fuse holder in engagement with an opposite side thereof from a side thereof which normally engages an end portion of a fuse, said switch blade being operable by said blade actuator and engageable with said stationary contact member.

2. A fusible electrical switch as claimed in claim 1, wherein said fuse holder closer to said stationary con tact member is a composite fuse holder including a relatively rigid portion and a resilient clamping portion, said switch blade being pivotally mounted on one side of the relatively rigid portion and the resilient clamping portion being adapted to hold one end portion of a fuse against the other side of the relatively rigid portion.

3. A fusible electrical switch as claimed in claim 1, wherein said fuse holder closer to said stationary contact member is a composite fuse holder including a relatively rigid portion and a resilient clamping portion, said switch blade being pivotally mounted on one side of the relatively rigid portion and the resilient clamping portion being adapted to hold one end portion of a fuse against the other side of the relatively rigid portion, and said resilient clamping portion having an extension extending on the other side of said switch blade from said relatively rigid portion and aiding in maintaining a good electrical connection between said switch blade and said relatively rigid portion.

4. A fusible electrical switch comprising a pair of aligned fuse holders adapted to hold a fuse, a stationary contact member mounted generally in alignment with said pair of fuse holders, a pivotally mounted blade actuator adjacent one of said fuse holders closer to said stationary contact member, a switch blade pivotally mounted on a portion of said one fuse holder in engagement with an opposite side thereof from a side thereof which normally engages an end portion of a fuse, said switch blade being operable by said blade actuator and engageable with said stationary contact member, and a biasing spring carried by said blade actuator, said spring establishing pressure between said stationary contact member and said switch blade when said switch blade is engaging said stationary contact member.

5. A fusible electrical switch as claimed in claim 4, wherein said spring aids in retaining said switch blade in pivotally mounted relationship with said one fuse holder.

6. A fusible electrical switch comprising an insulating base, a pair of aligned fuse holders mounted on said base and adapted to hold a fuse, a stationary contact member mounted on said base and spaced generally in alignment with said pair of fuse holders, a blade actuator pivotally mounted on said base adjacent one of said fuse holders closer to said stationary contact member, a switch blade pivotally mounted on a portion of said one fuse holder in engagement with an opposite side thereof from a side thereof which normally engages an end portion of a fuse, said switch blade being operable by said blade actuator and engageable with said stationary contact member, and a biasing spring carried by said blade actuator, said spring establishing pressure between said stationary contact member and said switch blade when said switch blade is engaging said stationary contact member.

7. A fusible electrical switch as claimed in claim 6, wherein said spring aids in retaining said blade actuator in pivotally mounted relationship with said base.

8. A fusible electrical switch as claimed in claim 6, wherein said spring aids in retaining said switch blade in pivotally mounted relationship with said one fuse holder.

9. A fusible electrical switch as claimed in claim 6, wherein said spring aids in retaining said switch blade in pivotally mounted relationship with said one fuse holder and in retaining said blade actuator in pivotally mounted relationship with said base.

10. A multipole fusible electrical switch comprising a plurality of pairs of aligned fuse holders, each pair of fuse holders respectively being adapted to hold opposite end portions of a fuse in substantially parallel relationship with fuses adapted to be held in other pairs of fuse holders, a plurality of stationary contact members mounted respectively generally in alignment with said pairs of fuse holders, an elongated pivotally mounted blade actuator adjacent fuse holders of each pair closer to their respective stationary contact members and extending transversely of the axes of fuses when fuses are mounted respectively in said pairs of fuse holders, and a plurality of switch blades pivotally mounted respectively on portions of said fuse holders of each pair in engagement respectively with opposite sides of said portions from sides thereof which normally respectively engage end portions of fuses, said switch blades being operable by said blade actuator and respectively engageable with said stationary contact members.

11. A multipole fusible electrical switch comprising a plurality of pairs of aligned fuse holders, each pair of fuse holders being adapted to hold a fuse in substantially parallel relationship with fuses adapted to be held in other pairs of fuse holders, a plurality of stationary contact members mounted respectively generally in alignment with said pairs of fuse holders, an elongated pivotally mounted blade actuator adjacent fuse holders of each pair closer to their respective stationary contact members and extending transversely of the axes of fuses when fuses are mounted respectively in said pairs of fuse holders, a plurality of switch blades pivotally mounted respectively on portions of said fuse holders of each pair in engagement respectively with opposite sides of said portions from sides thereof which normally respectively engage end portions of fuses, said switch blades being operable by aid blade actuator and respectively engageable with said stationary contact members, and a plurality of biasing springs carried by said blade actuator, said spring respectively establishing pressure respectively between said stationary contact members and said switch blades when said switch blades are respectively engaging said stationary contact members.

12. A multipole fusible electrical switch as claimed in claim 11, where-in said springs respectively aid in retaining said switch blades respectively in pivotally mounted relationship with said fuse holders of each pair closer to said stationary contact members.

113. A multipole fusible electrical switch as claimed in claim 11, wherein said springs aid in retaining said blade actuator in its pivotal mounting.

14. A multipole fusible electrical switch comprising an insulating base, a plurality of pairs of aligned fuse holders mounted on said base, each pair of fuse holders being adapted to hold a fuse in substantially parallel relationship with fuses adapted to be held in other pairs of fuse holders, a plurality of stationary contact members mounted on said base and respectively spaced generally in alignment with said pairs of fuse holders, a blade actuator pivotally mounted on said base, a plurality of switch blades operable by said blade actuator, each switch blade having one end portion pivotally mounted on the one fuse holder of a pair closer to its respective stationary contact member to accommodate pivoted movement of the switch blade about an axis substantially coaxial with the pivotal axis of said blade actuator, the other end portion of each switch blade being engageable with its respective stationary contact member, a plurality of electrical connectors respectively electrically connected to said stationary contact members, a plurality of electrical connectors respectively electrically connected to the other fuse holders of said pairs of fuse holders, said springs aiding in maintaining said blade actuator in pivotally mounted relationship with said base, and each spring aiding in maintaining said one end portion of a switch blade in pivotally mounted relationship with its respective fuse holder and establishing pressure between said other end portion of the switch blade and its respective stationary contact member when the other end portion and its respective stationary contact member are in engagement with each other.

15. A fusible electrical switch comprising an insulating base, a pair of aligned fuse holders mounted on said base and adapted to hold a fuse, a stationary contact member mounted on said base and spaced generally in alignment with said pair of fuse holders, a blade actuator pivotally mounted on said base adjacent one of said fuse holders closer to said stationary contact member, a generally flat elongated switch blade mounted for edgewise pivotal movement on a portion of said one fuse holder in engagement with an opposite side thereof from a side thereof which normally engages an end portion of a fuse, said switch blade pivoting in opposite directions upon corresponding movement of said blade actuator respectively to slidingly engage and disengage said stationary contact member, and a biasing spring carried by said blade actuator, said biasing spring establishing pressure between said stationary contact member and said switch blade when said blade is engaging said stationary contact member.

(References on following page) 10 References Cited 3,202,77 8/ 1965 Tillson ZOO-J62 X UNITED STATES PATENTS 3,308,256 3/1967 Carlyle 200-114 Van Valkenburg 200-3 FOREIGN PATENTS Hammann 20() 15 954,900 4/1964 Great Britain.

Hammerly 20015 5 Smith et ah BERNARD A. GILHEANY, Primary Examiner. Miller 200-114 H. E. SPRINGBORN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,346,711 October 10, 1967 Tadeusz J. Rys et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 23, for "mounting" read mountings line 51, for "carried" read carrier column 6, line 5, for "known" read know column 8, line 10, for "aid" read said line 37, for "pivoted" read pivotal line 45, after "holders," insert and a plurality of springs carried by said blade actuator,

Signed and sealed this 22nd day of October 1968.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

1. A FUSIBLE ELECTRICAL SWITCH COMPRISING A PAIR OF ALIGNED FUSE HOLDERS ADAPTED TO HOLD OPPOSITE END PORTIONS OF A FUSE, A STATIONARY CONTACT MEMBER MOUNTED GENERALLY IN ALIGNMENT WITH SAID PAIR OF FUSE HOLDERS, A PIVOTALLY MOUNTED BLADE ACTUATOR ADJACENT ONE OF SAID FUSE HOLDERS CLOSER TO SAID STATIONARY CONTACT MEMBER, AND A SWITCH BLADE PIVOTALLY MOUNTED ON A PORTION OF SAID ONE FUSE HOLDER IN ENGAGEMENT WITN AN OPPOSITE SIDE THEREOF FROM A SIDE THEREOF WHICH NORMALLY ENGAGES AN END PORTION OF A FUSE, SAID SWITCH BLADE BEING OPERABLE BY SAID BLADE ACTUATOR AND ENGAGEABLE WITH SAID STATIONARY CONTACT MEMBER. 